urradi C

Plasmatic Prekallikrein and Kallikrein Inhibitor in Pregnancy, Labor and in Newborn

In order to reveal the possible physiological role of the kallikrein during the stress of birth, the prekallikrein and kallikrein inhibitor were evaluated in 15 pregnant women and in 15 newborns from terminated pregnancies. The results show a very low level of prekallikrein in the funiculus blood at the moment of birth and a still lower level in venous blood 24 hours after birth. No important changes resulted in the mothers blood either in pregnancy, nor at the end of the labour.

Histamine and Kallikrein System in Man

Histamine infusion modifies the kallikrein system, studied by kaolin contact method, in man. The main modifications are the increase of the spontaneous esterase activity and the prekallikrein lowering. Apparently the histamine administration activates the kallikrein, and consequently a release of kinin can take place.

The Possible Role of Tryptophan in Migraine

For many years, it has been accepted that the serotoninergic system plays a major role in the modulation of nociception.

Urinary excretion of kallikrein during myocardial infarction

Although there is an overwhelming avidence that urinary kallikrein (KAL) is significantly decreased in several types of experimental and clinical hypertension, the physiological significance of the renal KAL-Kinin system is still uncertain. In order to clarify the involvement of this system in kidney excretory function, urinary KAL was measured in rats submitted to hyperhydration (5% b.w.) and sodium overloading with 2% NaCI solution given by stomach tube. Acetazolamide (10 mg) and furosemide (2.5-5 mg) induce significant increase in KAL excretion, particulary in NaCI loaded rats. Total KAL in renal tissue, measured in rats 2 hours after furosemide and water administration, showed a 15% decrease (p <0.01 ) compared to the hydrated controls. The loss of KAL in renal tissue can not be accounted for by the 280% increase of KAL in urine, particulary in animals injected for several days with furosemide. This result is in keeping with the idea that an accelerated synthesis of KAL under furosemide takes place in the kidney. KAL excretion in NaCI loaded rats is significantly higher (93%, p<0.005) than that recorded in hyperhydrated with tap water. Maximal KAL excretory rate was found in rats overloaded with 2% NaCI solution and injected with furosemide. In the dialysed urine collected in 2 hours after injection and tested in rat uterus (direct method: Croxatto and San Mart~n), an amount equivalent te 2666 + 601 ng of bradykinin was found, versus 240 + 28 ng of a normal hydrated rat. These results support the hypothesis that KAL is basically involved in the kidney function dealing with salt and water excretion.

Kallikreinogen-Kallikrein System During Muscular Work in Patients with Intermittent Claudication: Influence of Taurine Treatment

In 1964, Sicuteri and coworkers observed that the muscular work carried out during a local artificially induced ischemia in an arm provoked a lowering of the plasmatic kininogen of the venous blood drawn from the antecubital vein, 5–10 minutes after the end of the exercise. Immediately after stopping the muscular work in ischemia, the kininogen levels were nearly unmodified (6).