The effect of horse placental tissue extracts and equine chorionic gonadotrophin on the proliferation of horse lymphocytes stimulated in vitro.

The research study investigated the effects of substances found in horse placenta and a hormone called equine chorionic gonadotropin (eCG) on the growth of horse lymphocytes (cells of the immune system). It found that both eCG and placenta extracts caused a decrease in lymphocyte proliferation, suggesting they have immunosuppressive properties. However, the placental inhibitory activity doesn’t seem to be associated with eCG content, indicating the hormone may not be responsible for the suppression.

Subjects and Materials

• This study involved the use of horse lymphocytes, horse placental tissue, and equine chorionic gonadotropin (eCG).
• Horse placental tissue was extracted at 80 days of gestation, along with an extract from a term (full-term) placenta.
• The eCG was obtained commercially, and two extracts were compared: one had an eCG concentration of 50 IU/ml, while the other contained only 1.7 IU/ml of eCG.

Methodology

• The extracts and eCG were added to a mixed lymphocyte culture, which is a laboratory setup designed to stimulate the proliferation (growth and division) of lymphocytes.
• The proliferation of lymphocytes was then observed and evaluated, with the aim of discovering any inhibitory (suppressive) effects on this process.

Findings

• The researchers found a dose-related inhibition of lymphocyte proliferation with commercial eCG preparations and placenta extracts. This means that as the concentration of these substances increased, the lymphocytes’ ability to proliferate decreased, which suggests their immunosuppressive activity.
• The term placenta extract, however, showed negligible inhibitory activity, indicating that the stage of gestation might be a factor in this phenomenon.
• The two extracts with varying eCG concentration both showed similar inhibitory effects, indicating that the suppression of lymphocyte proliferation is likely unrelated to eCG levels. Alternatively, it suggests that commercial eCG could contain inhibitory contaminants.

Conclusions

• In conclusion, the study reveals that both extracts from horse placenta taken at 80 days gestation and commercial eCG preparations show inhibitory effects on horse lymphocyte proliferation, attributes which may be used to suppress immune response.
• However, it also posits that the hormone eCG itself may not be responsible for this suppression, indicating a need for further study to identify the actual inhibitors.