Modulators of Bufo arenarum ovulation.
In this study we investigated ovulation in vitro using ovary samples from Bufo arenarum with respect to their response to stimulation with homologous pituitary homogenate (HPH) or with progesterone and prostaglandins (PGF2alpha and PGE1) as intermediates of pituitary action. Ovary samples were obtained from animals captured during the breeding period. Our results demonstrate that the ovulatory response to all different inducers was dose dependent, the highest percentage of ovulated oocytes being obtained with HPH treatment. An important increase in the ovulatory response was obtained by the association of PGF2alpha with either HPH or progesterone at suboptimal doses, indicating that this prostaglandin induced a synergistic potentiating effect. Incubation with cyclooxygenase inhibitors (indomethacin or diclofenac sodium) produced a significant decrease in the ovulation induced by HPH, demonstrating that prostaglandins are involved in the action of the pituitary gland in this process. According to our results, PGE1 not only had no participation in the ovulatory process, but also produced an inhibitory effect on ovulation induced by HPH treatment.
Ramos
Inés
I
Instituto Superior de Investigaciones Biológicas, Departamento de Biología del Desarrollo, Universidad Nacional de Tucumán, Argentina, Chacabuco 461, Tucumán, Argentina. inramos@fbqf.unt.edu.ar
Cisint
Susana B
SB
Crespo
Claudia A
CA
Medina
Marcela F
MF
Fernández
Silvia N
SN
D000818:Animals; D002022:Bufo arenarum / Q000502:physiology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D005260:Female; D009865:Oocytes / Q000502:physiology; D010053:Ovary / Q000187:drug effects* / Q000254:growth & development; D010060:Ovulation / Q000187:drug effects / Q000502:physiology*; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism; D011374:Progesterone / Q000494:pharmacology*; D011453:Prostaglandins / Q000494:pharmacology*
D016861:Cyclooxygenase Inhibitors; D011453:Prostaglandins; D011374:Progesterone