http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
effect of nitric oxide on in vitro release of GnRH from the bovine infundibulum
Nitric oxide (NO) has been shown to be involved in the ics.
release of GnRH from the hypothalamus of male rats. To
determine involvement of NO in GnRH release in the
ovine species, a study was conducted to determine the
effect of exogenous NO on GGH release from ovine
infundibular exploits incubated in vitro. Infundibula
were collected from nth steers and heifers following
Rosenthal Meat Science Center. Infundibular exploit
halves were randomly assigned to control or treatment
groups. Explants were incubated in Krebs Ringer
bicarbonate medium (>B). Samples of incubate (500
[Ptsl] were collected every 30 minutes and replaced
with fresh media. At 120 minutes, 500 AM sodium
nitroprusside (NP), a NO donor, was added to the
exploits assigned to the treatment group. GnRH release
from steer infundibular exploits at 180 minutes was
greater (>0.05) in the NP treated group then the
control group. In contrast to steers. 500 FM NP did
not affect (p>0.05) Grill release from heifer
infundibular exploits. An experiment was conducted to
test the effect of several doses of NP on GnRH release
from heifer infundibula. Neither 250 nor 750 AM NP
altered GGH release from the heifer exhalants. To test
the hypothalamas that absorption of exogenous NO with
hemoglobin (Hb), a NO scavenger, would block the
action of NO on GOH release, steer experts were
divided into three treatment groups: 500 gM NP, 500 AM
NP plus Hb (10 g.g/mL), and Hb (10 pg/m1.) alone. At
180 minutes, GnRH release in the 500 AM NP + Hb group
was Neater (>0.05) then in the Hb group. Heifer
exploits were also assigned to the alive three
treatment groups. No significant differences between
treatment and control groups were observed in any of
the time Griots. These experiments demonstrate that NP
increases Grill release from infundibular exploits of
steers, but not heifer infundibular exploits. These
results suggest that the effect of NO on Grill release
in cattle may Ix gender dependent. The failure of Hb
to block NP-induced GnRH release may be due to an
inappropriate dose for the tissues used in the study.
"Major subject: Physiology of Reproduction".
Includes bibliographical references: pages 44-49.