  The effect of interplanetary plasma on pulsed pulsar radiation passing
through is considered. The pulses of two rotating radio transients (J0609+16,
J1132+25) and a pulsar (B0320+39) detected on the Large Phased Array (Pushchino
observatory) were analyzed. It is shown that in observations at the frequency
of 111 MHz, on elongations of 20o-40o, both an increase and a decrease in the
number of received pulses are observed. The change in the number of pulses is
explained by the distortion of the energy distribution of pulses due to
interplanetary scintillation. These changes in the number of observed pulses
are in qualitative agreement with the expected dependence of the scintillation
index on the observed sources elongation. Analytical expressions are obtained
that allow estimating the effective modulation index from observations of
individual pulses for the power distribution of pulses by energy.
