Elevated catecholamine levels and mono aminooxidase activity in the hypophysis of EWES following hormonal stimulation with serum gonadotropin.
The effect of hormonal stimulation on catecholamine levels and activity of its degradation enzyme monoaminooxidase in the hypophysis of ewes in the estric period was studied by the radioenzymatic method. The estrus of ewes was synchronised with Agelin sponges (Agelin, Spofa) containing 20 ug chlorosuperlutin. After completed synchronisation we induced superovulation in the experimental group by means of 2000 IU serum gonadotropin. Catecholamines were determined radioenzymatically using the Catechola test. Monoaminooxidase activity was determined radiochemically. The results indicate that hormonal serum gonadotropin stimulation increases significantly (P < 0.01) pituitary dopamine and epinephrine levels in ewes. In comparison with the control group norepinephrine concentration did not change in this tissue. MAO activity in the hypophysis decreased significantly to almost one half in comparison to control values (P < 0.001). According to our results serum gonadotropin in combination with hyperestrogenisation influences selectively dopamine and norepinephrine metabolism in the hypophysis of hormonally stimulated ewes and reduces monoaminooxidase activity.
Pástorová
B
B
Department of Physiology, University of Veterinary Medicine, Kosice.
Várady
J
J
Kozácková
M
M
D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D004837:Epinephrine / Q000378:metabolism; D004971:Estrus / Q000187:drug effects; D005260:Female; D006062:Gonadotropins / Q000097:blood / Q000494:pharmacology*; D008995:Monoamine Oxidase / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D010904:Pituitary Gland, Posterior / Q000187:drug effects / Q000378:metabolism*; D012756:Sheep; D013268:Stimulation, Chemical; D013480:Superovulation / Q000187:drug effects
D002395:Catecholamines; D006062:Gonadotropins; D008995:Monoamine Oxidase; D009638:Norepinephrine; D004837:Epinephrine