Oxytocic activities in human pituitary gland on sudden death (author's transl)

Abstract

Oxytocin has been known to be released by females during delivery or lactation, but it has physiological significance for males which, as might well be supposed, has not yet been made clear. We can conjecture that it has some use in wide scope homeostasis.Some sudden unexpected natural deaths are essentially negatie with regard to classical autopsy findings and the true causes of such deaths can not be found even by employing both gross and microscopic examinations and toxicologic analyses. In the best of medico legal institutions the rate of negative autopsies ranges from 2 to 10 per cent of the total cases examined.Typical diseases for which autopsy findings are negative are the Sudden Infant Death Syndrome (SIDS) and the Sudden Manhood Death Syndrome (SMDS). These are included as sudden unexpected natural deaths where the patients are outwardly healthy, the past histories, of patients are not predictive of death and the convincing causes of the deaths can not be found out by means of the conventional postmorten examinations. Attention, however, has not been paid to SMDS in Europe and in the U.S. as has been done in Japan.In sudden unexpected natural deaths, there is little doubt that certain biochemical disturbances may be operating. However, these have not been identified as yet under the current status of our knowledge, but physiological and biochemical study promise to be fruitful areas of investigation in the future.To examine how oxytocin corresponds to SMDS, I examined 151 cases of various sudden death (male 116, female 35), in the age range of from 20 to 81 and compared the weight of each human pituitary gland, knewing that female pituitary glands are heavier than those of males. But we must also investigate if there is any relation with cerebral swelling in agony.With the Chicken Depressor Method, I examined oxytocic activities of 53 adult pituitary glands (male 36, female 17) and got the following results.1) No significant difference of oxytocic activity in the human pituitary glands was discerned between males (7.42±0.86U/gland) and females (7.53±1.03U/gland).2) The oxytocic activity is not determined by age, it is not decreased even at the advanced age of over seventy.3) The oxytocic activity decreases only shortly 34 hours after postmortem.4) From pituitary gland removed after death, I could not find if oxytocin has diurnal variation of biological rhythm, but this does not prove that it has not so long as the correct method of quantity of level in the blood is not completed.5) The most prominent character found in the measurement of oxytocic activity using human pituitary glands, is that the amount of oxytocin release differs according to causes of sudden death. I noticed a significant difference between SMDS and the group of cardiac arrests by negative autopsy which has usually been classified into the former in Japan.When the cause is SMDS, the oxytocic acitivity measures 3.99 ±0.60 U/gland, while it measures 10.33±1.20 U/gland when the casuse is cardiac arrest. The low level of oxytocic activity at SMDS closely resembles that of the group of brain death (4.03 ± 1.34 U/gland).6) So two assumptions can be drawn. One is oxytocin from pituitary gland release is more for SMDS than cardiac arrest. The other is that low level oxytocic activity may be causes by the low storage unable to keep up the amount released in the pituitary gland by the amount synthesized at hypothalamus, as the amount of oxytocin stored in the pituitary gland being balanced between it is the amount synthesized and released.