Effects of FSH and LH on incorporation of [3H]thymidine into follicular DNA.
To assess the roles of FSH and LH on follicular growth, after various experimental manipulations, hamster follicles were sorted into 10 stages and incubated for 4 h with [3H]thymidine. Stages 1-4 correspond to follicles with 1-4 layers of granulosa cells, respectively; Stage 5 = 5 or 6 layers of granulosa cells plus theca; Stage 6 = 7-8 layers of granulosa cells plus theca; Stage 7 = early formation of the antrum; Stages 8-10 = small, intermediate and large antral follicles, respectively. Phenobarbitone sodium injected at 13:00 h on pro-oestrus blocked the normal rise of blood FSH and LH concentrations at 15:00 h and prevented the increase of [3H]thymidine incorporation into follicles of Stages 1-9. The optimal treatment to reverse the effects of phenobarbitone was 1 microgram FSH and 2 micrograms LH injected i.p. at 13:00 h which restored DNA replication to follicles of Stages 2-10: FSH acted primarily on Stages 2-5 and LH on Stages 5-10. Injection of phenobarbitone at 13:00 h on prooestrus followed by 2.5 micrograms FSH at 22:00 h restored DNA synthesis by the next morning to follicles at Stages 1-8. In hamsters hypophysectomized at 09:00 h on the day of oestrus (Day 1), injection on Day 4 of 2.5 micrograms FSH restored DNA synthesis 6 h later to Stage 2-6 follicles. Unilateral ovariectomy on Day 3 resulted 6 h later in an acute rise in FSH and LH and change of follicles from Stage 4 to Stage 5 but, paradoxically, there was decreased synthesis of DNA in follicles of Stages 5-10.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D006224:Cricetinae; D046508:Culture Techniques; D004247:DNA / Q000378:metabolism*; D004261:DNA Replication / Q000187:drug effects; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000502:physiology*; D007016:Hypophysectomy; D007986:Luteinizing Hormone / Q000502:physiology*; D008647:Mesocricetus; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism*; D010052:Ovariectomy; D010634:Phenobarbital / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism* / Q000494:pharmacology
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D004247:DNA; D013936:Thymidine; D010634:Phenobarbital