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Biomedical subjects

T Nomoto

Publications and source records attributed to T Nomoto.

At least 145 records · Page 8Linked to original sources
PubMed1980

Myogenic receptivity for Met-enkephalin in the rat duodenum: comparison with the guinea-pig duodenum.

Met-enkephalin (ENK) induced a dose-dependent transient relaxation in vitro in the rat duodenum while morphine neither induced a response nor affected the response to ENK. The response was not blocked by tetrodotoxin but was abolished by naloxone. The response of guinea-pig duodenum to ENK was either relaxation or pulsatile contractions depending on the dose and was abolished by tetrodotoxin.

Animals↗
PubMed1980

Effects of thyrotropin-releasing hormone (TRH) on the isolated small intestine and taenia coli of the guinea pig.

Thyrotropin-releasing hormone (TRH) produced a contraction in the isolated segment of duodenum and taenia coli of the guinea-pig (pA2, 8.0 and 8.9). TRH induced a contraction, a relaxation, or a contraction followed by relaxation in the jejunum and ileum. All the responses to TRH of the small intestine and the taenia coli were abolished in the presence of tetrodotoxin but not affected by hexamethonium. The contractile response to TRH of the small intestine was abolished and replaced by a relaxation in the presence of hyoscine. This relaxant response was not affected by guanethidine. The taenial response to TRH was partially inhibited by either hyoscine or methysergide and markedly diminished by the two together. These findings indicate that TRH acts on the myenteric neurons of the small intestine and taenia coli of the guinea pig. The contractile response of small intestine is likely to be induced through cholinergic nerves while cholinergic, serotonergic and unidentified excitatory neurons seem to be involved in the taenial response. These neurogenic actions of TRH on the guinea-pig intestine are in contrast with the myogenic natur of the response to TRH in the duodenum of the rat.

Animals↗
PubMed1979

Effect of intracerebroventricular administration of thyrotropin-releasing hormone upon the electroenteromyogram of rat duodenum.

Electroenteromyographic activity (EMG) of the duodenum was recorded in pentobarbital-anesthetized rats. TRH intraventricularly administered to rats produced changes in EMG such as increased amplitude, decreased frequency of slow waves and the association of bursts of spike potentials with nearly every cycle of the basal electric rhythm (BER). The effect was selectively prompt and marked in the EMG of proximal duodenum. The response was abolished by vagotomy or atropine injection and no response was elicited in the neonatally 6-OHDA-treated rat. Hypophysectomy, cord-transection or acute i.v. injection of 6-OHDA did not block the response. In the brain, TRH seems to stimulate the neuronal system controlling the vagus efferents involved in the regulation of the duodenal enteric nervous system which in turn modulates the myogenic excitability of the duodenum.

Animals↗
PubMed1979

[Role of brown adipose tissue in the thermal response to chlorpromazine in rats during cold exposure (author's transl)].

Significance of the intercapsular brown adipose tissue (IBAT) in the thermal response to chlorpromazine (CPZ) during acute and chronic cold exposure was studied in rats. Adult male Wistar-Imamichi rats were exposed to 4 degrees C for 1 (cold-exposed) or 30 days (cold-acclimated). Intraperitoneal injection of 10 mg/kg CPZ caused a more marked and lasted hypothermia in acute cold-exposed rats as compared with that seen in control or in cold-acclimatized rats. Hypothermia induced by CPZ was unaffected by removal of IBAT either in control or acute cold-exposed rats. But in cold-acclimated rats, the removal of IBAT potentiated the hypothermia by CPZ. The relative weight of IBAT in cold-acclimated rats was about 3 times heavier than that in control and acute cold-exposed rats. CPZ had no effect on the relative weight of IBAT in all groups examined. Total lipids in IBAT showed no significant changes following CPZ administration in rats of all groups. In acute cold-exposed rats, serum FFA level progressively decreased after CPZ injection. The noradrenaline concentration in IBAT increased after chronic cold exposure and CPZ suppressed this elevation. The results suggest that the thermogenesis related sympathetic activity in the IBAT plays a mediatory role in thermal response to CPZ during cold acclimation.

Acclimatization↗
PubMed1979

Central nervous system mediated stimulation by thyrotropin-releasing hormone of microcirculation in thyroid gland of rats.

The blood flow of thyroid, adrenal cortex and renal cortex in the pentobarbital anesthetized rat was assessed from hydrogen gas desaturation curve. The microcirculation of thyroid was markedly augmented within 2 min after an intraventricular injection of Thyrotropin-Releasing Hormone (TRH) while Met-Enkephalin (ENK) failed to influence. Both TRH and ENK stimulated the microcirculation of adrenal cortex moderately. ENK diminished the microcirculation of renal cortex whereas TRH did not exert any effect. The response of thyroid to TRH was abolished by vagotomy, thus the existence of a specific TRH-vagus -thyroid connection was indicated.

Adrenal Cortex↗