Terminal cardiac electrical activity in adults who die without apparent cardiac disease

Prolonged electrocardiographic (Holter) recording was performed to analyze terminal electrical events in 23 hospitalized adults who died without apparent cardiac disease. Most patients showed a gradual slowing of heart rate with shifting of cardiac pacemaker downward from the sinus node or atria to the atrioventricular junction and ventricles, resulting in cardiac asystole. Dominant bradyarrhythmia was more common than ventricular tachyarrhythmia (83 vs 17%). Agonal ST-segment elevation was not uncommon (26%). These terminal electrical events became manifest from 1 to 450 minutes (mean 62) before cessation of cardiac electrical activity. Forty-eight percent of the patients continued to show deteriorating sinus or atrial activity up to the last moment. The mechanism of bradycardiac asystole in patients with no apparent cardiac disease may be attributed to generalized anoxic and toxic depression of the sinus node and subsidiary pacemakers, together with neurogenic suppression of these structures.

Dermorphin-like immunoreactivity in guinea pig and rat stomach

Dermorphin is an opioid peptide containing one D-amino acid isolated from amphibian skin. We examined the presence of dermorphin-like immunoreactivity (DMP-IR) in mammalian brain and tissues using an antiserum developed in our own laboratory which works at a dilution of 1:120,000 for Radioimmunoassay (RIA) and can detect 2.1 pg of dermorphin. We were unable to find DMP-IR in guinea pig, rat and toad brain and rat and toad spinal cord either extracted with methanol or with HCl. The guinea pig and rat stomach contained significant amounts of DMP-IR (228.9 pg/mg protein and 97.5 pg/mg protein respectively) when extracted with HCl but not with methanol. The DMP-IR we detected in the stomach is not dermorphin per se. A single peak of DMP-IR was found on Sephadex G-25 gel filtration. When re-chromatographed on reverse phase HPLC, this peak of DMP-IR gave rise to three peaks of DMP-IR.

Enkephalin involvement in acupuncture analgesia-radioimmunoassay

Since there are several endogenous morphine-like substances differing in distribution and probably also in function, it seems necessary to study their roles in acupuncture analgesia separately. Therefore we set up a sensitive and specific radioimmunoassay (RIA) for met- and leu-enkephalin, and employ it in determining the changes of enkephalin contents in the brain regions and CSF during acupuncture. The main results are as follows: (i) Two enkephalins increase markedly in hypothalamus and striatum during acupuncture analgesia. (ii) Prior intraventricular bacitracin enhances the acupuncture analgesia with concomitant increased contents of enkephalins in the brain and CSF. (iii) Cycloheximide, the protein-synthesis inhibitor, reduces the enkephalin-increasing effect of acupuncture, indicating that one of the mechanisms by which acupuncture elevates the enkephalin levels is the acceleration of biosynthesis. (iv) After surgical isolation of rat hypothalamus, the effect of electric acupuncture is attenuated. This indicates that hypothalamus takes part in acupuncture analgesia.