[Determination of conjugated and free estrogen in male plasma (authors transl)]

Radioimmunoassay for conjugated and free estrone (E1), estradiol-17beta(E2) and estriol (E3) in male plasma was investigated, while no precise determination of conjugated estrogen in male plasma had been established. Each tritiated estrogen glucuronides for determining the recovery was added to 3 ml of plasma samples. These plasma samples were extracted with acetone, hydrolyzed with 15 vol% HCl at 100 degrees C for 60 minutes, and resulting free estrogens were extracted with ether. These extracts were washed with 1% NaOH and 1% NaHCO3, and applied to microcolumn of Sephadex LH-20. Then they were determined by the radioimmunoassay as the same method of evaluation for free estrogen. Each mean values of plasma free and conjugated estrogen in 10 normal adult males was as follows: 36.0 +/- 9.81 pg/ml(free E1), 29.5 +/- 11.0 pg/ml(free E2), 1.80 +/- 1.27 pg/ml (free E3), 31.0 +/- 12.6 pg/ml (conjugated E1), 36.0 +/- 14.2 pg/ml (conjugated E2), 30.6 +/- 8.35 pg/ml (conjugated E3). Conjugated estrogen to free estrogen ratio was 1.45.

Inhibition of hypoglossal motoneurons by stimulation of the jaw-opening muscle afferents

The synaptic linkage of jaw-opening muscle afferents with the retractive and the protrusive motoneurons (R-Mns and P-Mns) in the hypoglossal motor nucleus was explored in anesthetized cats. It was found that stimulation of low-threshold afferents arising in the jaw-opening muscles (m. mylohyoideus and m. digastricus) evoked IPSPs in both R-Mns and P-Mns with about 10 to 15 msec latencies. By injecting Cl ions into R-Mns or P-Mns, the hyperpolarizing postsynaptic potentials evoked by jaw-opening muscle afferent impulses were reversed to depolarizing potentials. The lingual-IPSPs of hypoglossal motoneurons were concluded to be dependent on increase of Cl conductance. Stimulation of low threshold lingual afferents evoked a reflex discharge in the retractive nerve fibers with a 6.0 msec latency and in the protrusive nerve fibers with a 5.5 msec latency. Inhibition of the linguohypoglossal reflex by stimulation of the jaw-opening muscle afferents was completely removed by an intravenous injection of strychnine (0.1 mg/kg) or picrotoxin (6 mg/kg). It is concluded that the low threshold afferents arising in the jaw-opening muscles are connected to both R-Mns and P-Mns and P-Mns through inhibitory synapses via a polysynaptic pathway.

Interrelation of afferent impluses from different bellies of the temporal muscle of the cat

A physiologic interaction of proprioceptive afferent impulses from the different muscle bellies of the temporal muscle were studied in the cat. The impulses from one belly of the temporal muscle modified the activities of the motoneurons innervating the different bellies of the muscle.