Catecholamine secretion by the adrenal medulla of the foetal and new-born foal.
Abstract: 1. The content and output of adrenaline and noradrenaline from the equine adrenal medulla has been investigated under different conditions in foetuses, foals and adult mares.2. In the foetus only small amounts of both amines were secreted in response to stimulation of the peripheral ends of the splanchnic nerves to the gland; during anoxia the adrenal discharge was far greater and was independent of any nervous mechanism.3. Whereas in the ruminant a direct adrenal response to low P(O2) is confined to the noradrenaline cells during foetal life only, the adrenal medulla of the foetal foal secreted both adrenaline and noradrenaline during asphyxia, and the direct response persisted for some days after birth. Noradrenaline was the amine predominantly released during asphyxia in the foetus.4. Catecholamine output from the equine adrenal medulla changed with age, in that there was a gradual increase in both the absolute and relative amount of adrenaline released, irrespective of the stimulus applied, although at any given stage of development a higher proportion of adrenaline was secreted in response to stimulation of the splanchnic nerves than during anoxia.5. The relative proportions of the two amines in the effluent blood bore little resemblance to those found in the glands, removed after prolonged asphyxia, in either foetuses or foals. Preliminary observations have indicated that more noradrenaline is present in the glands when the foetus remains relatively undisturbed within the uterus.6. The possible significance of the larger adrenal response to asphyxia in the foetal foal in comparison with other species is discussed in relation to the development of the innervation and the growth of the adrenal cortex.
Publication Date: 1971-08-01 PubMed ID: 5565643PubMed Central: PMC1331928DOI: 10.1113/jphysiol.1971.sp009546Google Scholar: Lookup
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- Journal Article
Summary
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The research paper analyses the secretion of adrenaline and noradrenaline from the adrenal medulla in foetuses, foals and adult mares under different conditions. This study highlights how the secretion changes in response to different stimuli and with age, and discusses its potential significance in relation to the development of the nervous system and growth of the adrenal cortex in foals.
Investigation of adrenal secretion
- The study investigated the content and output of adrenaline and noradrenaline from the equine adrenal medulla. These compounds are produced in response to stress and are essential for the body’s fight-or-flight response.
- In foetuses, only small amounts of these amines were secreted when the peripheral ends of the splanchnic nerves to the gland were stimulated. Anoxia, or lack of oxygen, precipitated a far greater adrenal discharge, which wasn’t dependant on any nervous mechanism.
Comparative observation between species
- The researchers found that unlike ruminants, where the adrenal response to low oxygen availability is limited to noradrenaline cells during foetal life only, the adrenal medulla of the foetal foal secreted both adrenaline and noradrenaline during asphyxia. The response continued for a few days following birth.
- During asphyxia, noradrenaline was the predominantly released amine in foetuses. This reveals a difference in the adrenal response between foetal foals and ruminants.
Changes in catecholamine output with age
- Adrenaline and noradrenaline output from the equine adrenal medulla increased progressively with age, regardless of the stimulus. A higher proportion of adrenaline was secreted in response to nerve stimulation than during anoxia at every stage of development.
- This pattern indicates that the adrenal medulla’s reaction changes with the growth and development of the animal.
Correlation between amines quantity in effluent blood and adrenal glands
- The relative proportions of adrenaline and noradrenaline in the effluent blood did not match those found in the adrenal glands removed after prolonged asphyxia in either foetuses or foals. In both cases, more noradrenaline was present when the foetus remained relatively undisturbed within the uterus.
Significance of adrenal response differences
- The research also discussed the potential implications of the higher adrenal response to asphyxia in foetal foals compared with those of other species. This phenomenon could be related to the development of nerve connections and the growth of the adrenal cortex, suggesting an adaptive biological response.
Cite This Article
APA
Comline RS, Silver M.
(1971).
Catecholamine secretion by the adrenal medulla of the foetal and new-born foal.
J Physiol, 216(3), 659-682.
https://doi.org/10.1113/jphysiol.1971.sp009546 Publication
Researcher Affiliations
MeSH Terms
- Adrenal Glands / blood supply
- Adrenal Glands / growth & development
- Adrenal Glands / innervation
- Adrenal Medulla / embryology
- Adrenal Medulla / metabolism
- Adrenal Medulla / physiopathology
- Age Factors
- Animals
- Animals, Newborn / metabolism
- Asphyxia / metabolism
- Carbon Dioxide / metabolism
- Denervation
- Epinephrine / metabolism
- Female
- Hexamethonium Compounds / pharmacology
- Horses
- Hydrogen-Ion Concentration
- Hypoxia / physiopathology
- Norepinephrine / metabolism
- Oxygen / blood
- Physiology, Comparative
- Pregnancy
- Splanchnic Nerves / physiology
References
This article includes 13 references
- Comline RS, Silver M. The development of the adrenal medulla of the foetal and new-born calf.. J Physiol 1966 Mar;183(2):305-40.
- Wurtman RJ, Axelrod J. Control of enzymatic synthesis of adrenaline in the adrenal medulla by adrenal cortical steroids.. J Biol Chem 1966 May 25;241(10):2301-5.
- Jost A. Problems of fetal endocrinology: the adrenal glands.. Recent Prog Horm Res 1966;22:541-74.
- Rossdale PD. Clinical studies on the newborn thoroughbred foal. I. Perinatal behaviour.. Br Vet J 1967 Nov;123(11):470-81.
- Bassett JM, Thorburn GD. Foetal plasma corticosteroids and the initiation of parturition in sheep.. J Endocrinol 1969 Jun;44(2):285-6.
- Comline RS, Silver M, Silver IA. Effects of foetal hypophysectomy on catecholamine levels in the lamb adrenal during prolonged gestation.. Nature 1970 Feb 21;225(5234):739-40.
- Comline RS, Silver M. PO2, PCO2 and pH levels in the umbilical and uterine blood of the mare and ewe.. J Physiol 1970 Aug;209(3):587-608.
- Redfern PA. Neuromuscular transmission in new-born rats.. J Physiol 1970 Aug;209(3):701-9.
- Comline RS, Nathanielsz PW, Paisey RB, Silver M. Cortisol turnover in the sheep foetus immediately prior to parturition.. J Physiol 1970 Sep;210(2):141P-142P.
- COMLINE RS, SILVER M. The release of adrenaline and noradrenaline from the adrenal glands of the foetal sheep.. J Physiol 1961 May;156(3):424-44.
- DIAMOND J, MILEDI R. A study of foetal and new-born rat muscle fibres.. J Physiol 1962 Aug;162(3):393-408.
- SILVER M. The output of adrenaline and noradrenaline from the adrenal medulla of the calf.. J Physiol 1960 Jun;152(1):14-29.
- COMLINE RS, SILVER IA, SILVER M. FACTORS RESPONSIBLE FOR THE STIMULATION OF THE ADRENAL MEDULLA DURING ASPHYXIA IN THE FOETAL LAMB.. J Physiol 1965 May;178(2):211-38.
Citations
This article has been cited 3 times.- Wood CE, Keller-Wood M. Current paradigms and new perspectives on fetal hypoxia: implications for fetal brain development in late gestation.. Am J Physiol Regul Integr Comp Physiol 2019 Jul 1;317(1):R1-R13.
- Macdonald AA, Colenbrander B, Versteeg DH, Heilhecker A, Wensing CJ. Catecholamines in fetal pig plasma and the response to acute hypoxia and chronic fetal decapitation.. Wilehm Roux Arch Dev Biol 1984 Jan;193(1):19-23.
- Motelica-Heino I, Roffi J. Norepinephrine in fetal and neonatal rabbit brain.. Experientia 1975 Oct 15;31(10):1166-7.
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