Eletroacupuntura para tratamento de hipotensão induzida por isofluorano em cavalos / Electroacupuncture treatment for isoflurane induced hypotension in horses

Objetivou-se avaliar a eficiência do tratamento da hipotensão arterial com eletroacupuntura comparativamente à dobutamina em equinos. Foram avaliados seis cavalos adultos, saudáveis, mantidos em anestesia inalatória, com isofluorano, em ventilação mecânica. Após a estabilização da anestesia, foi induzida hipotensão arterial, através do incremento da concentração do isofluorano, iniciando-se um dos tratamentos: DOB: dobutamina (1,5µg kg-1 min-1, infusão contínua intravenosa); EA: estímulo elétrico no acuponto pericárdio 6 (PC6), bilateralmente; SHAM: estímulo elétrico em ponto falso de acupuntura. Foram mensurados: frequência cardíaca (FC), pressão arterial média (PAM), temperatura retal (T), concentração final expirada de isofluorano (ETiso), variáveis hemogasométricas, concentração sérica de aspartato aminotransferase (AST) e creatina fosfoquinase (CK), tempo e qualidade da recuperação pós-anestésica. Houve incremento na PAM de 50%, 36,6% e 7,5% nos tratamentos DOB, EA e SHAM, respectivamente. Não houve diferença entre os grupos nas variáveis hemogasométricas, FC, T, ETiso, CK, AST, tempo e qualidade de recuperação pós-anestésica. Conclui-se que o tratamento com dobutamina foi mais efetivo para o tratamento da hipotensão em cavalos sob anestesia inalatória quando comparado ao estímulo elétrico do acuponto PC6 ou ponto falso de acupuntura...

This study aimed to evaluate the efficacy of electroacupuncture compared to the dobutamine treatment of hypotension in equines. Six adult horses were maintained in isoflurane anesthesia with mechanical ventilation. After anesthesia was established, the isoflurane concentration was raised until hypotension was achieved. After that the animals were treated with a constant rate of 1.5mg kg -1min-1 intravenous dobutamine (DOB), electroacupunture to pericardium 6 (PC-6) acupoint (EA) and false point treatment (SHAM). Heart rate (HH), median arterial blood pressure (MAP), rectal temperature (T), isoflurane end-tidal concentration, arterial blood gases, creatine kinase (CK), aspartate transaminase (AST), recovery time and quality of recovery were investigated. The MAP increased 50%, 36.5% and 7.5%% in DOB, EA and SHAM treatments, respectively. HH, T, arterial blood gases, CK, AST, recovery time and quality of recovery did not differ among treatments. It was concluded that the dobutamine treatment was more effective than EA and SHAM treatments for the reversion of isoflurane induced hypotension in horses...

M and P retinal ganglion cells of the owl monkey: morphology, size and photoreceptor convergence.

We have estimated photoreceptor convergence to M and P retinal ganglion cells of two closely related nocturnal (owl monkey, Aotus) and diurnal (capuchin monkey, Cebus) anthropoids. Rod convergence is higher in the owl monkey retina while cone convergence to both M and P cells are very similar in the retinas of the owl monkey and the capuchin monkey. These results indicate that during evolution, the owl monkey retina has undergone changes compatible with a more nocturnal lifestyle, but kept a cone to ganglion cell relation similar to that found in diurnal primates.

Conservation of absolute foveal area in New World monkeys. A constraint on eye size and conformation.

The foveal specializations of five New World monkeys, the marmoset, Callithrix jacchus; the golden-handed tamarin, Saguinus midas niger; the squirrel monkey, Saimiri ustius; the capuchin monkey, Cebus apella; and the howler monkey, Alouatta caraya were compared. Although retinal area varies by over a factor of two in these monkeys, the area of the fovea does not covary with retinal area and remains approximately the same absolute size, as measured by the dimensions of the high density region of cones, or the rod-free region. This constancy in foveal size also holds for rhesus monkeys and humans, bringing the variation in retinal area to a factor of five. Alouatta caraya is unusual, distinguished by a very high central cone density and a small rod-free zone. Physiological constraints that might limit foveal area over a wide range of eye sizes are considered.