Table 13

Effect of combined and repeated hormone treatments on the growth of Tetrahymena

(Csaba, G., Németh, G. Effect of combined and repeated hormone treatment on the growth of the Tetrahymena. Acta Biol. Hung. 33, 87-89, 1982)

Groups

Day	1	2	3	4	5	6	7	8	9
1	T2	Gr	5HT	Gr+T2+5HT	Gr+T2+5HT	Gr	T2	5HT	Control
3	5HT	5HT	T2	-	Gr+T2+5HT	GR	T2	5HT	Control
5	Gr	T2	Gr	-	Gr+T2+5HT	GR	T2	5HT	Control
14	Gr+T2+5HT	Gr+T2+5HT	Gr+T2+5HT	Gr+T2+5HT	Gr+T2+5HT	Gr	T2	5HT	Control
Mean cell count	13.5	15.5^*+&	16.2^*+$	13.5	13.6^o	14.4*	21.0^*+&	23.6^*+&	12.5

Significance to control (group 9): p<0.05= ^o; p<0.01= *

Significance to group 1: p<0.01= ⁺

Significance to group 4: p<0.01= ^&

Conclusions:

1. Gramine (Gr), T₂ (diiodotyrosine) and 5HT (serotonin) alone stimulated growth of Tetrahymena.

2. These three molecules applied simultaneously extinguished the effect of each other.

3. Applied in sequence depress, however not necessarily extinguish, the effects of one another.