Electrical stimulation of the vagus nerves produces an excitatory
contraction response in the isolated rat stomach. This contraction
response was abolished by atropine to unmask the vagal inhibitory
response (VIR) elicited during low frequency vagal stimulation.
Babring and Gershon (1967), after working on guinea-pigs and mice,
hypothesized that both serotonin...
Pineal acetylserotonin methyltransferase (ASMT) activities
in rainbow trout were reported on by Hafeez and Quay (1971). The validity of certain
assay parameters used by these researchers
were investigated. With the exception of incubation temperature,
all parameters studied proved to be quite valid. Temperature
studies indicated a low stability for trout...
Biliary excretion has been of considerable interest in mammals
but has not been extensively studied in fish. To understand the
significance of biliary excretion in rainbow trout (Salmo gairdneri),
two studies were conducted.
The objective of the initial study was to evaluate the ability of
rainbow trout to excrete a...
Tissue distribution studies of calcium and lead in brain tissue
of rats were increased subsequent to a single intravenous injection
of lead, 10 mg/kg, in the form of lead acetate. Time-course
studies demonstrated that brain concentrations of calcium and lead
(in terms of wet tissue weight) were found to be...
The utero-ovarian vasculature of domestic animals has been a
popular research subject, especially concerning the roles of the uteroovarian
artery and vein in the unilateral luteolytic phenomenon
demonstrated in these animals. No reports in the literature, however,
have been found regarding the smooth muscle physiology of these vessels.
The present...
Neuromuscular physiology has been extensively investigated
in several groups of vertebrates excluding fish. To
understand the nature of neuromuscular transmission in this
group, the response of the pectoral fin abductor muscle of
black bass (Micropterus salmoides) to nerve stimulation
under the influence of an anticho1inesterase agent was
studied. Diisopropylfluorophosphate (DFP),...
Pineal hydroxyindole-0-methyltransferase (HIOMT) activity
was monitored over a 24 h period under three different photoperiods,
16L:8D, 8L: 16D, and 12 L:12D. It was observed that in all three
groups of fish HIOMT activity was high' during the dark portion of the
photoperiod in comparison to activity during the light portion....
The performance of an organism or organismic subsystem is
the result of the interaction between the performance capacity of
the system and Its environment. Environmental conditions can
stress an organism and thus affect it's performance. In this
study, three whole organism performances were examined: critical
swimming speed, fatigue time and...
Non-vascularized hearts of buffalo sculpin (Enophrys bison)
were used to investigate the cardiac toxicity of compounds that
cause methemoglobinemia. The affinity of sculpin cardiac myoglobin
for oxygen (P50 = 1.10 torr at 20 C°, pH 7.8) was lower than that of
mammals studied (P50 = .44 and .76 torr for...