L Krulich

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The hyt/hyt mouse (BALB/cBY-hyt, C.hytRF) provides a useful model for exploring the effect of inherited severe primary hypothyroidism. Studies were undertaken to try to define the basis of the primary hypothyroidism in mice homozygous for the autosomal recessive gene, hyt. These mice had congenital hypothyroidism of fetal onset after 15 days post(More)
The aim of this work was to study the role of the dorsal noradrenergic ascending pathway (DNAP), which originates in the locus coeruleus (LC) on the preovulatory surge of luteinizing hormone (LH) follicle-stimulating hormone (FSH) and prolactin (PRL) by producing bilateral electrolytic lesions (cathodal or anodal) in this nucleus. LC lesions were placed at(More)
Unanesthetized adult male rats with indwelling right atrial cannulae were used in the majority of experiments. Morphine (MOR, 3.0 mg/kg) caused a large but transient increase in both GH and PRL levels, which could be prevented with naloxone. Disruption of central noradrenergic function with diethyldithiocarbamate (400 mg/kg) or phenoxybenzamine (15 mg/kg)(More)
The effects of bremazocine and U-50,488, two selective opioid kappa receptor agonists, and the preferential mu receptor agonist morphine on the secretion of PRL and GH were compared in conscious male rats bearing permanent right atrial cannulae for serial blood sampling and drug delivery. All three opioids stimulated PRL secretion in a dose-related manner,(More)
A number of sites have been hypothesized as loci at which opioid substances act to alter the secretion of luteinizing hormone (LH) and prolactin (PRL) (1-8). The aim of the present study was to determine the site(s) at which the opioid peptide beta-endorphin (beta-END) acts to influence plasma LH and PRL levels in the ovariectomized (OVX) rat. beta-END,(More)
An analysis of the GH release-inhibiting action of the opioid kappa receptor agonists bremazocine and U-50,488, established earlier, was attempted by testing the agonists against activation of GH secretion by morphine or clonidine in male rats bearing right atrial cannulae for serial blood sampling and drug delivery. Both kappa agonists inhibited the effect(More)
Administration of opioid receptor antagonists was utilized to determine the opioid receptor type involved in the suppression of LH release by beta-endorphin (beta-END). Long-term (three to four weeks) ovariectomized rats with chronic third ventricular cannulae were fitted with jugular catheters and received treatment with vehicle or one of three opioid(More)
To determine the localization of luteinizing hormone-releasing hormone (LHRH), five brains from adult male rats were serially sectioned in a cryostat at - 10 C in either the frontal, horizontal or sagittal planes. Acetic acid-ethanol extracts of each section were assayed for LHRH using radioimmunoassay (RIA) and in some cases using bioassay as well.(More)