Topic:Glucose
Glucose is a simple sugar that serves as a primary energy source for horses. It is metabolized through various biochemical pathways to support cellular functions and overall energy requirements. In equine physiology, glucose levels are influenced by factors such as diet, exercise, and metabolic health. Monitoring glucose concentrations is important for understanding metabolic conditions, such as insulin resistance and equine metabolic syndrome, which can affect a horse's health and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the regulation, metabolism, and clinical implications of glucose in equine health.
Tissue glycogen and glucose 6-phosphatase levels in fetal and newborn foals. Glycogen and glucose 6-phosphatase levels were measured in a variety of tissues from fetal, newborn and adult pregnant mares. Hepatic and renal glucose 6-phosphatase activities increased with increasing gestational age and rose further in the 24 h after birth to values similar to those observed in maternal tissues. The glycogen content of fetal liver and skeletal muscle also increased in late gestation, whereas that of fetal lung and cardiac muscle decreased toward term. No significant change in renal glycogen content with fetal age was observed. The values of hepatic glycogen and glucose 6-ph...
Influence of pregnancy on diurnal and seasonal changes in glucose level and activity of FDPA, AlAT and AspAT in mares. 1. The diurnal changes in the glucose level and in activity of FDPA, A1AT and AspAT in four pregnant standard-bred mares were studied. 2. As a control four barren mares, were kept and examined in the same conditions. 3. Blood samples were taken every 4 hr for one day, each month, throughout pregnancy, or one year. 4. A diurnal rhythm in activity of A1AT and AspAT in barren mares was found. The pregnancy masked diurnal rhythm in activities of both transaminases. 5. No diurnal rhythm in glucose level and FDPA activity in both groups of mares was observed. 6. Seasonal cyclicity was found in all i...
Selected laboratory parameters of thoroughbreds. Selected haematological, blood chemical and serological variables were investigated in healthy Thoroughbreds (n = 45) in training. Haemoglobin concentration, haematocrit, red, white and differential cell counts as well as serum concentrations of total and ionized calcium, sodium, potassium, chloride, urea, creatinine, total protein, albumin, inorganic phosphorus, total bilirubin, iron, glucose, magnesium, alkaline phosphatase, gamma-glutamyltransferase, lactate dehydrogenase, aspartate transaminase, alanine transaminase and creatine kinase were found to be within ranges previously reported for...
The stress response to anaesthesia in ponies: barbiturate anaesthesia. Information on the equine stress response to anaesthesia and surgery is sparse but offers a promising approach to elucidating the high anaesthetic risk in this species. Previous work has shown that halothane anaesthesia induces substantial metabolic and endocrine changes. This paper reports the effects of barbiturate anaesthesia. Anaesthesia was induced with thiopentone in six ponies and no further agents were given. They stood within 30 mins. On another occasion, these animals, and three further ponies, were anaesthetised with pentobarbitone and anaesthesia was maintained for 2 h. No surgery ...
Metabolic and hormonal changes associated with arthroscopic surgery in the horse. The effect of general anaesthesia and arthroscopic surgery on blood glucose and lactate, plasma non-esterified fatty acids, insulin, beta-endorphin and cortisol was investigated in seven horses. Animals were premedicated with xylazine and anaesthesia was induced with guaifenesin and sodium thiamylal and maintained with halothane vaporised in oxygen. Blood samples were collected in the pre-, intra- and post operative period. Induction of anaesthesia was associated with a transient hyperglycaemia and a significant rise in plasma insulin levels. Plasma insulin values fell during surgery but showe...
[The horses of Giara: variation of the thyroid activity and certain blood parameters between winter and summer]. The changes of some parameters in the blood serum of six Giara horses (3 males and 3 females) were checked weekly, in relation to the environmental temperature throughout a one winter and summer. T3, total lipids, triglycerides, urea nitrogen, creatinine, total protein, albumin, beta and gamma globulin showed significant difference between winter and summer and, with the exception of triglycerides, urea nitrogen and total protein were correlated to the environmental temperature. T4, glucose, uric acid and alpha globulin showed no difference between the two seasons and no correlation with the t...
Partial pressures of oxygen and carbon dioxide, pH, and concentrations of bicarbonate, lactate, and glucose in pleural fluid from horses. Samples of pleural fluid from 20 horses with effusive pleural diseases of various causes were evaluated; samples from 19 horses were used for the study. There were differences for pH (P = 0.001) and partial pressure of oxygen (PO2) between arterial blood and nonseptic pleural fluid (P = 0.0491), but there were no differences for pH, PO2, partial pressure of carbon dioxide (PCO2), and concentrations of bicarbonate (HCO3-), lactate, and glucose between venous blood and nonseptic pleural fluid. Paired comparisons of venous blood and nonseptic pleural fluid from the same horse indicated no differe...
A field study of post-exercise values of blood biochemical constituents in jumping horses: relationship with score, individual and event. The variability of the post-exercise values (PEV) of blood lactate and of some other blood constituents were studied in 8 healthy and fit jumpers through 5 national competitions of equal difficulty. The effects of factors such as the individual, performance and competition on these PEV were analysed. Venous blood was sampled immediately after the 5 show-jumping contests and was analysed for packed cell volume (PCV), blood lactate, blood glucose (GLU), total plasma protein (TPP), bicarbonate (HCO3-), sodium (Na+), potassium (K+), chloride (Cl-), calcium (Ca2+), serum activities of lactate dehyd...
Haematological, biochemical and physiological changes in horses and ponies during the cross country stage of driving trial competitions. The haematological, biochemical and physiological changes associated with the cross-country stage of driving trials were studied in horses and ponies competing in singles, pairs, tandems and teams at five, five-section and two, three-section events. Heart rates were monitored continuously and sometimes exceeded 200 beats/minute. The highest maximum, mean and recovery heart rates were found after the most severe competitions. Rectal temperatures were also highest after the most severe events and in some animals exceeded 41 degrees C. Respiratory rates were very variable. Blood taken five minute...
Mycoplasmas from donkeys and horses in the Sudan. Seventeen isolates (4.27%) were recovered from 398 samples. Twelve isolates (4%) were obtained from 300 donkey nasal swabs, three (4.3%) and two (6.89%) isolates were recovered from 69 horse nasal swabs and 29 mare uterine washings, respectively. Nine isolates were lost during storage at -20 degrees C and the remaining eight were identified as mycoplasmas and their biological, biochemical and serological reactions were investigated. The isolates could be divided into two groups on the basis of glucose fermentation and arginine hydrolysis. The first group neither fermented glucose nor hydrolyse...
Effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature in neonatal foals. The effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature were investigated in six foals at 10 and 28 days of age. These variables were also measured in three foals at 19 days of age when saline alone was injected. Rectal temperature fell significantly after 30 mins in both groups of xylazine treated foals and was still depressed after 120 mins. Hypothermia did not occur in the saline control group. There was no significant change in blood glucose or plasma insulin concentrations during the 120 mins following either xylazine or saline administrat...
[The content of Hb and the hematocrit value in blood and the total proteins, urea, glucose, free fatty acids, Na, K, Ca, Mg, Pa, Fe, Fe-binding capacity, Cu and Zn in the blood plasma of Warmblood horses during feeding with oat-hay or barley-hay rations over a period of 9 months]. 4 horses (Group A) received an oat-hay ration, through 9 months running, while 3 horses (Group B) were fed a barley-hay ration over the same period of time. Blood samples were collected and examined in 4-week intervals. All values considered, no differences were found to exist between the 2 groups with regard to Hb and haematocrit in blood as well as to protein, glucose, sodium, potassium, magnesium, iron fixation capacity, copper, and zinc in blood plasma. The urea level in plasma of Group A was higher than that in Group B, values being 5.76 +/- 0.64 mmol/l and 5.14 +/- 0.72 mmol/l. The same ...
Action of dexamethasone in an equine model of acute non-immune inflammation. In a crossover study in seven New Forest ponies the actions of dexamethasone, at a dose rate of 0.06 mg kg-1 administered intravenously, were compared with those of a placebo treatment. Dexamethasone exerted expected effects on plasma and inflammatory exudate concentrations of cortisol and on blood glucose concentration and circulating leucocyte numbers, but it failed to affect exudate concentrations of the eicosanoids, prostaglandin E2, thromboxane B2, 6-keto-PGF1 alpha and leukotriene B4. These findings do not support the hypothesis that the anti-inflammatory actions of dexamethasone in the ...
Equine stress responses to anaesthesia. Information on equine stress responses to anaesthesia and surgery is sparse. Six ponies were anaesthetized for 2 h with halothane and no surgery was performed. Plasma concentrations of glucose, lactate, non-esterified fatty acids, cortisol, insulin, catecholamines and adrenocorticotropic hormone (ACTH) were measured. The results were compared with those obtained in the same group of ponies over the same time period on a different day with the animals conscious. Anaesthesia induced an increase in plasma concentrations of glucose, lactate, cortisol and ACTH and a decrease in plasma concentration...
Effects of allopurinol in experimental endotoxin shock in horses. The effect of allopurinol pretreatment 12 hours before an intraperitoneal challenge with a sublethal dose of Escherichia coli endotoxin (50 micrograms kg-1) was evaluated in 18 horses. The horses were divided among three equal groups: 1-endotoxin alone; 2-5 mg allopurinol kg-1 bodyweight plus endotoxin; and 3-50 mg allopurinol kg-1 bodyweight plus endotoxin. A variety of evaluation parameters were used. No differences among the groups were noted in rectal temperature, heart rate, respiration rate, haematological values, blood PaO2, blood PaCO2, blood pH or blood bicarbonate. Significant (P les...
Effects of phenylbutazone on glucose tolerance and on secretion of insulin in healthy geldings. The effect of phenylbutazone (4.4 mg/kg of body weight, IV, q 24 h, for 5 days) on glucose tolerance and on secretion of insulin in 6 healthy geldings was determined. Phenylbutazone significantly lowered fasting concentrations of glucose in plasma but did not significantly change the concentration of insulin in serum. There was no significant effect of phenylbutazone on glucose tolerance, on secretion of insulin, or on the area under the insulin/glucose ratio vs time curve in healthy geldings, as determined by paired t test analysis.
Blood chemistry and skeletal muscle metabolic responses during and after different speeds and durations of trotting. Eight standardbred horses trotted on a treadmill for 55 mins at a sub-maximal speed of 5m/sec and subsequently performed an exercise test consisting of 2 min intervals at increasing speed. Heart (HR) and respiratory (Rf) rates and venous blood samples were obtained before, during and for 5 mins after exercise. Gluteus medius muscle biopsies and rectal temperatures were taken before and after exercise. The mean HR was 132/min and the mean Rf was 156/min during the 5m/sec trotting. With 5m/sec exercise, plasma free fatty acids (FFA), glucose, creatinine and cortisol concentrations increased mark...
Echinococcus granulosus: a comparison of free amino acid concentration in hydatid fluid from primary and secondary cysts and host plasma. A total of 28 components were detected in the free amino acid (FAA) pool of hydatid fluid from primary and secondary equine cysts, secondary ovine cysts and host plasma. Examination of data from equine cysts revealed that the majority of FAAs were present in significantly greater concentrations in secondary cysts, glycine being over 30 times more concentrated. Values for total carbohydrates and glucose did not, however, differ significantly and total protein content was greater in primary cysts. Comparison of the (FAA) pool of secondary equine and ovine cysts revealed strain variation. It was ...
A study of diurnal changes in cortisol and glucose levels and FDPA activity in foals during the first 13 weeks of life and in their lactating mothers. 1. In six standard-bred mares and their foals diurnal changes in the cortisol and glucose levels and in FDPA activity were studies for 13 weeks of foal life. 2. In the cortisol level diurnal rhythm was found in the 3rd, 7th and 11th week of foal life and in the 11th week of lactation in mares. 3. In mares the mean diurnal cortisol level changed from 32 ng/ml in the first week to 57 in the 11th week and in foals from 24 in the first week to 16 ng/ml in the 11th week. 4. In the glucose level no diurnal rhythm was observed. 5. In mares the mean diurnal glucose level after parturition was about 58...
[Performance testing of mules and Haflinger horses used as pack animals]. During 20 weeks blood constituents in peripheral blood (Erythrocyte count, Packed cell volume, Hemoglobin, Sedimentation rate, activities of Aspartate aminotransferase, Alanine aminotransferase, Creatine phosphokinase, Lactate dehydrogenase, Lactate dehydrogenase-1-isoenzyme, Glucose, Lactate, Total bilirubin), pulse and respiration rate were determined at rest and after exercise. Significant increase of blood values after exercise could be noted in relation to the intensity of exercise and the performance of the animals. The well trained horses had an increase of their performance according t...
Metabolism of naturally occurring [13C]glucose given orally to horses. In 5 horses, 13CO2/12CO2 ratios in expired air were determined using isotope mass spectroscopy to investigate metabolism of naturally occurring [13C]glucose. Oral glucose tolerance tests (OGTT) were performed using maize or beet glucose. Maize has a higher 13C concentration than that of most plants. The 13CO2/12CO2 ratios after OGTT was performed using maize glucose were compared with 13CO2/12CO2 ratios in expired air after OGTT was performed using beet glucose. The ratio also was determined during the period horses were not fed. Using OGTT, all horses were glucose tolerant. The OGTT performed...
Dietary requirements and athletic performance of horses. There is no clear evidence that the chronic requirement for any non-energy yielding nutrient rises in proportion as the energy requirement increases with hard work. The need for protein, and probably that for calcium, remain a function of bodyweight daily. Some proportionality with energy may exist for certain nutrients, although the evidence has not been adduced. For example, because of an increase in both the proportion and amount of propionic acid in the volatile fatty acids of caecal contents, the tissue requirement for vitamin B12 may rise with an increase in the rate of energy metabolism...
Progressive myotonia in foals resembling human dystrophia myotonica. A severe and progressive neuromuscular disorder accompanied by clinical, electrophysiological, and pathological features resembling human dystrophia myotonica was observed in three foals. This disorder was apparent as early as 1 month of age and involved progressive skeletal muscle dysfunction, initially characterized by proximal muscle hypertrophy and hypertonicity with subsequent muscle stiffness, weakness, and atrophy. Multisystem involvement was manifested in one case by testicular hypoplasia, early cataract formation, and borderline glucose intolerance. Prolonged dimpling of these large r...
Adrenocorticotropin-containing neoplastic cells in a pars intermedia adenoma in a horse. Pituitary-dependent hyperadrenocorticism was diagnosed in a 14-year-old Arabian mare with chronic weight loss, hirsutism, polyuria, and polydipsia. The mare had a stress leukogram, glucosuria, and consistent hyperglycemia. Plasma glucose concentrations were resistant to suppression by insulin. Plasma cortisol concentrations were within normal limits, but did not respond to dexamethasone suppression and had an exaggerated response to ACTH stimulation. At necropsy, a chromophobe adenoma of the pars intermedia of the pituitary gland was found. The zona fasciculata of the adrenal cortex and the pa...
Responses of blood glucose, insulin and cortisol concentrations to common equine diets. Two experiments were conducted to determine the response of blood glucose, insulin and cortisol levels to four common equine diets. Experiment 1 was designed to determine the diurnal variation of glucose and two glucoregulatory hormones, insulin and cortisol, in four fasting geldings. No diurnal variation was observed in either glucose or insulin levels during the 24-h sampling period. However, cortisol levels did exhibit a circadian rhythm, with elevated values observed in the morning and low values in the evening. Experiment 2 investigated the response of glucose, insulin, cortisol and selec...
Neuroendocrine changes produced by competition stress on the Thoroughbred race horse. 1. Packed cell volume (PCV) and plasma catecholamines, cortisol and glucose were determined in blood samples obtained from race horses, after competition. 2. All these parameters were higher than basals but catecholamines increased 6-7 times while cortisol was enhanced only by 25%. 3. The increase of glucose and PCV was related to the rise of catecholamines. 4. In samples withdrawn after overnight stress caused by change of horseshoes, it was not possible to find values from basal values significantly different. 5. Influence of nervous temperament was observed only in the higher hematocrit fou...
Glucose metabolism in a pony mare with a tumour of the pituitary gland pars intermedia. A case of pituitary dependent hyperadrenocorticism in a horse is reported. Clinical signs included hirsutism, polydipsia and general debility. The horse was persistently hyperglycaemic and glucose values were unchanged following subcutaneous administration of insulin. Resting cortisol values were normal, but dexamethasone suppression of cortisol concentration was shorter than normal. Plasma glucose, cortisol, insulin and glucagon concentrations were measured as part of an intravenous glucose tolerance test. The patient responses were different from those in a control pony.
Metabolic responses to exercise in the racehorse: changes in plasma alanine concentration. Previous studies in humans have shown that alanine is released from the skeletal muscle in proportion to the work load. We have measured plasma alanine and urea concentrations in well-trained Standardbred and Finnish-bred (cold-blooded) trotters after a graded-intensity exercise and during recovery to study metabolic responses to exercise in this animal model. As controls we measured blood lactate, pyruvate, and glucose concentrations as well as hematocrit values. Metabolic responses to exercise were closely reflected in all these parameters. Plasma alanine increased relatively more than plasm...
Some metabolic and hormonal changes associated with general anaesthesia and surgery in the horse. Three different anaesthetic techniques were studied in normal, healthy Thoroughbred or Thoroughbred type horses. These were (a) acepromazine, thiopentone and suxamethonium; (b) acepromazine, glyceryl guaiacolate and a 'half-dose' of thiopentone; and (c) xylazine and ketamine. Anaesthesia was maintained with halothane vaporized in oxygen and nitrous oxide. All horses underwent either laryngeal or body surface surgery. Heart rate, packed cell volume, blood glucose and lactate, plasma non-esterified fatty acids, insulin and cortisol were measured before, during and after surgery. The greatest met...
Metabolic and hormonal responses to neuroleptanalgesia (etorphine and acepromazine) in the horse. Administration of etorphine and acepromazine to horses was associated with an increase in haematocrit, blood glucose, blood lactate and plasma non-esterified fatty acids (NEFA). The rise in plasma NEFA was most striking following injection of the antagonist diprenorphine and could contribute to the production of cardiac arrhythmias. Plasma insulin was depressed at the end of surgery. These changes, plus profuse sweating, are indirect evidence of strong sympathetic stimulation. Plasma cortisol did not alter significantly due to wide individual variation. Venous blood pH fell, reflecting the ris...