Nociceptin/orphanin FQ (N/OFQ) is the endogenous ligand for the N/OFQ peptide receptor (NOP). N/OFQ causes hypotension and vasodilation, and we aimed to determine the role of histamine in inflammatory microvascular responses to N/OFQ. Male Wistar rats (220-300 g, n = 72) were anesthetized with thiopental (30 mg/kg bolus, 40-90 mg x kg(-1) x h(-1) iv), and the mesentery was prepared for fluoresc...

Histamine elevates the intracellular cyclic AMP levels in cultured embryonic chick retinal pigment epithelium. The half-maximal activity is 6 X 10(-6) M. The effect of histamine is mediated by H2 receptors, i.e., inhibited by the H2 antagonist cimetidine and not affected by the H1 antagonists diphenhydramine and pyrilamine. The inhibition constant (KI) of cimetidine is 1.3 X 10(-8) M. Thus, the...

Gly-Leu-Phe (GLF), an immunostimulating peptide derived from alpha-lactalbumin, prevented alopecia induced by an anticancer agent etoposide in a neonatal rat model after intraperitoneal injection at a dose of 100 mg/kg for 4 d or oral administration at a dose of 300 mg/kg for 6 d. By microscopic analysis of skin sections, GLF proved to inhibit etoposide-induced loss of hair, thickening of the e...

In the present study, effects of intracerebroventricular (icv) administration of histamine, mepyramine (H1-receptor antagonist) and famotidine (H2-receptor antagonist) have been investigated on the formalin test in rats. Subcutaneous injection of formalin (50 microl, 1%) into the ventral surface of the left hind paw produced a marked biphasic pain response (first phase: 0-5 min and second phase...

At there ambient air temperature range, the rectal temperature changes following infusion of histamine either into lateral ventricle (L.V.) or IVth ventricle (IVth V) were studied. At an ambient temperature range of 19-22 degrees C, hypothermia occurred following histamine infusion either into L.V. or IVth V. Hypothermia elicited from infusion of histamine into L.V. was prevented with pretreatm...

1 Histamine and 2-methyl-histamine (H1-receptor agonist) caused dose-dependent increases in capillary permeability in albino mice, but 4-methyl-histamine (H2-receptor agonist) caused no significant increase. 2 Mepyramine (H1-receptor antagonist) blocked the histamine-induced increase in capillary permeability whereas burimamide (H2-receptor antagonist) produced no significant blockade of the hi...

The precise mechanism(s) underlying the thermal hyperemic response to local heating of human skin are not fully understood. The purpose of this study was to investigate a potential role for H1 and H2 histamine-receptor activation in this response. Two groups of six subjects participated in two separate protocols and were instrumented with three microdialysis fibers on the ventral forearm. In bo...