In Dahl salt-sensitive (S) rats, Na(+) entry into the cerebrospinal fluid (CSF) and sympathoexcitatory and pressor responses to CSF Na(+) are enhanced. Salt-inducible kinase 1 (SIK1) increases Na(+)/K(+)-ATPase activity in kidney cells. We tested the possible role of SIK1 in regulation of CSF [Na(+)] and responses to Na(+) in the brain. SIK1 protein and activity were lower in hypothalamic tissu...

We have recently reported that the central heme oxygenase (HO) pathway has an important role in the genesis of lipopolysaccharide fever. However, the HO product involved, i.e., biliverdine, free iron, or carbon monoxide (CO), has not yet been identified with certainty. Therefore, in the present study, we tested the thermoregulatory effects of all HO products. Body core temperature (T(c)) and gr...

This study examined the effect of intracerebroventricular leptin on insulin sensitivity in streptozotocin (STZ)-induced diabetic rats. Male Wistar rats were cannulated in the lateral ventricle and, after recovery, administered either intravenous STZ (50 mg/kg) to induce diabetes or citrate buffer. Chronic leptin (10 microg/10 microl icv) or vehicle injections were administered daily for 14 days...

Nishimura, Masato, Ken Ohtsuka, Akira Nanbu, Hakuo Takahashi, and Manabu Yoshimura. Benzamil blockade of brain Na1 channels averts Na1-induced hypertension in rats. Am. J. Physiol. 274 (Regulatory Integrative Comp. Physiol. 43): R635–R644, 1998.—To determine the possible involvement of brain amiloride-sensitive Na1 channels in Na1-induced hypertension, we investigated the effects of benzamil hy...

Leptin plays a critical role in the central regulation of bone mass. Ghrelin counteracts leptin. In this study, we investigated the effect of chronic intracerebroventricular administration of ghrelin on bone mass in Sprague-Dawley rats (1.5 μg/day for 21 days). Rats were divided into control, ghrelin ad libitum-fed (ghrelin ad lib-fed), and ghrelin pair-fed groups. Ghrelin intracerebroventricul...

Intracerebroventricular infusion of the peptide melittin increases immunoreactive kinins in the cerebrospinal fluid of anesthetized dogs, probably secondary to activation of brain or cerebrospinal fluid kininogenases. Intracerebroventricular melittin also increases blood pressure and heart rate, possibly mediated by brain kinins, since intracerebroventricular bradykinin also increases blood pre...

The influence of prolonged ingestion of ethanol on stimulation of water or ethanol intake by intracerebroventricular infusion of ANG II was evaluated in rats. Animals were maintained for 5-6 mo with either 10% ethanol solution or water as their only source of fluid. In both groups of rats, infusion of ANG II caused a large increase in water intake (7-fold) and a lesser increase in 10% ethanol i...