RESUMO
We examined the hypothesis that right handers and left handers may differ in sensory perceptions and respiratory responses to J receptor stimulation with intravenous injections of lobeline HCl in incremental doses. The comparison was made between 6 right handers and 9 left handers (all males) for (i) the dose of lobeline required to produce sensory threshold (viz., first appearance of respiratory sensations) and cough threshold (first appearance of cough); and (ii) latency and duration of sensations for sensory and cough threshold. All these comparisons were not found to be significant statistically. The sensation of breathlessness, and feelings of drowsiness, giddiness and headache were perceived in 3 of the 9 left handers, and in none of the right handers, but the difference was not significant. Reflex bradycardia was recorded only in left handers (5 of 9). The time (sec) for cough threshold was negatively correlated to threshold dose of lobeline (r = -0.5, and P < 0.05). The left handers perceived cough at the threshold as more distressing as compared with right handers (VAS P < 0.05). In conclusion, handedness did not influence J receptor responses to i.v. lobeline.
Assuntos
Adulto , Lateralidade Funcional , Humanos , Lobelina/farmacologia , Masculino , Sistema Respiratório/efeitos dos fármacos , Células Receptoras Sensoriais/efeitos dos fármacos , Estimulação QuímicaRESUMO
Hypertonic solutions of different substances were injected into the vertebral artery of dogs anesthetized with chloralose, preventing their access to the hypothalamic osmoreceptors by ligating the basilar artery and both the external carotid arteries. The hypertonic solution of sodium chloride produced graded inhibition of water diuresis and a concomitant rise in plasma antidiuretic hormone (ADH) level; hypertonic solution of glucose produced lesser effect. Hypertonic urea solution, on the other hand, did not alter the course of water diuresis. It was concluded that osmoreceptors are also present in the medulla which sense the changes in blood osmolarity and accordingly modify the ADH release.