Abstract:
Introduction: In recent decades chronobiology - a science that studies the regularities of the functioning of the organism, especially biological rhythms is developing rapidly.
Biorhythms are stable nonstopper lifetime fluctuations with individual amplitude-frequency characteristics. Kidneys are characterized by a clear time organization of functions
too, however, the peculiarities of circadian organization and the mechanisms of the participation of intracellular messengers in particular nitrogen monoxide (NО) in biorhythmic
regulation of renal functions, remain insufficiently studied
The aim of our work was to investigate the peculiairities of the influence nitrogen monoxide synthesis blockade on circadian organization of kidney acid-regulating function
under conditions of pineal gland hyperfunction.
Materials and methods: The experiments were conducted on 72 mature non-linear albino male rats with their body mass 0,15-0,18 kg. The animals were kept under
vivarium conditions at a stable temperature and air humidity fed on a standard dietary intake. The control group included animals (n=36) kept under conditions of usual light
regimen (12.00L:12.00D) during 7 days. The experimental group included animals (n=36) injected with N-nitro-L-arginine (L-NNA) in the dose of 20 mg/kg during 7 days under
conditions of continuous absolute darkness (12.00D:12.00D). On the 8th day the animals were exposed to 5% water load with heated to room temperature water supplied and
the parameters of the kidney acid-regulating function under conditions of forced diuresis were investigated.
Results: The inhibition of the monoxide synthesis (NО) in conditions of pineal gland (PG) hyperfunction violated the structures of chronorhythms acid-regulating function of
the kidneys. The decrease in urine pH at daytime intervals was due to a decrease in the level of hydrogen ion excretion during this period of the day. The introduction of the NО
blocker against the background of the PG hyperfunction violated the structure of the acid esterification chronorhythms that are titrated. The maximum level of this indicator was
recorded at 20.00 a.m. a day. The blockade of the synthesis NО on the background of the PG hyperfunction significantly reduced the level of excretion of ammonia.
Conclusions: The maximum level of excretion was 12.00 a.m., bathyphase - at 24.00 a.m. The average daily level was 1.5 mcmol/100 mcl GF and was lower relative to the
control animals and animals that were in the conditions of PG hyperfunction.
